I thought it would be interesting (at least to me, and hopefully to my readers) to see how this might work in real life. So here is a series of snapshots of today's workday:

Got to work (read: stepped on to the treadmill desk) @ 7:58am

Walked for 56 minutes before heading out to a 9am appointment

Got back to the office (read: stepped back on...) @ 10:10am

Walked for 84 minutes before heading out for lunch with D
Got back to the office @ 12:50pm
Walked for 30 minutes before jumping off for an afternoon meeting
Got back to the office @ 2:05pm
Walked for 46 minutes before heading out the door to pick up kids
Got back to the office @ 4:15pm
Walked for 57 minutes and then went downstairs to think about cooking dinner.

So...on a typical day I might walk nearly 5 hours while at work, covering 6.82 miles, and burning (at least according to my tread) 1200 calories